Knitting machine needle



H. C. NOE

KNITTING MACHINE NEEDLE Filed March 1'7, 1954 Dec;24, 1957 2,817,222

INVENTOR & glam/a!0.11/28 KNITTING MACIflNE NEEDLE Harold C. Noe, UpperMontclair, N. J., assignor to Kidde Manufacturing Co., Inc., Bloomfield,N. J., a corporation of Delaware Application March 17, 1954, Serial No.416,790

6 Claims. (Cl. 66-121) The present invention relates to needles forknitting machines, and, more particularly, to such needles of the latchtype.

Latch needles generally comprise a shank having a longitudinal slotformed in the front face thereof, a hook at the upper end of the shankhaving a bend of about 180, and a latch pivotally mounted in the slotand having a spoon at its free end adapted to engage the point of thehook when the latch is in its closed or upper position. When the latchis in its open or lower position, the back of the spoon is adapted toengage the cheeks of the shank which define the latch receiving slot.

Heretofore, such needles were considered satisfactory for use inconnection with knitting machines, for example of the Raschel type,which were operated at speeds of about 100 to 200 courses per minute.However, in the past five years, Raschel knitting machines have beenimproved in such a manner that they can now be operated at speeds ofabout 500 to 600 courses per minute. As a consequence of these highoperating speeds, excessive breakage of the heretofore satisfactoryconventional latch needles has been experienced. The time consumed inreplacing broken needles thereby somewhat offsets the time gained byfaster operation, with the net result that the fabric output of themachines is not materially increased.

Such needle breakage is attributed to the fact that, when the machinesare operated at high speeds, the force acting on the latch to swing itup and down greatly increases the kinetic energy of the latch, suchenergy being a function of the square of the needle velocity. Ittherefore follows that needle breakage is induced when the fast movinglatch strikes stationary portions of the needle and the latch ismomentarily brought to rest.

It has been discovered that needle breakage occurs at the hook and atthe cheek portions below the pivot. The former breakage is primarily dueto the fact that the latch strikes the point of the hook to exert abending moment thereon which creates a strain concentration at about themidpoint of the bend of the hook when such forces are applied at highfrequencies. The latter breakage is primarily due to the fact that therounded or somewhat V-shaped back of the spoon seeks to enter the slotwhen the latch is swung down either by inertia or the pull of the yarn.This imparts a combined wedging and hammering action of the spoon on theedges of the cheeks, whereby the cheeks are chipped or slivered andeventually crack to cause what is known as check breakage. Also, thisresults in the roughening of the latch and cheeks to an extent wherebythe thread being knitted is subjected to being frayed or severed uponengaging the impaired cheeks.

Accordingly, the present invention aims to overcome needle breakage andimpairment due to the foregoing or other causes.

An object of the present invention is to provide a latch needle suitablefor use in connection with knitting ma- 7 chines operated at high speedswhich is simple, practical and economical in construction.

nited States Patent f Patented Dec. 24, 1957 "ice Another object is toprovide such a needle which will resist hook or point breakage.

A further object is to provide such a needle which will resist cheekbreakage or impairment thereof.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

In accordance with the present invention, the foregoing objects areaccomplished by providing a needle having a hook which resists breakagethereof and having a spoon which cooperates with the checks to preventbreakage or impairment thereof.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description, and is shown in the accompanying drawing,forming a part of the specification, wherein:

Fig. 1 is a side view of the upper portion of a latch in its upper orclosed position.

Fig. 2 is a similar View with the latch in its lower or open position.

Fig. 3 is a front view of the needle as shown in Fig. 1.

Fig. 4 is a sectional view taken along the line 4-4 on Fig. 1.

Fig. 5 is a sectional view taken along the line 5-5 on Fig. 2.

Fig. 6 is a fragmentary side view of the hook.

In Figs. 1 to 3, the needle is shown on an enlarged scale of about 25 to1; whereas, in Figs. 4 to 6, the scale is about 50 to 1.

Referring to the drawing in detail, there is shown a needle generallycomprising a shank 10 and a latch 11. The shank has a hook 12 at itsupper end and is formed with a longitudinal slot or groove 14 at thefront face thereof defined by cheeks 15 (Fig. 3). The latch is pivotallymounted in the groove by a pin or rivet 15 and has a spoon 18 at itsfree end adapted to contact the point of the hook.

As shown in Figs. 4 and 5, the face of the spoon is recessed or dishedout in the conventional manner. However, the back of the spoon, insteadof being rounded or V-shaped, is formed in a manner to prevent wedgingitself between the cheeks. This is accomplished by forming the back ofthe spoon with a generally rectangular lengthwise extending rib 20having a width slightly less than that of the slot 14 and about equal tothat of the body or blade of the latch. At the shallow or lower portionof the spoon (as viewed in Fig. 1), the back of the spoon has a pair ofshoulders 21 which meet the rib 20 at about right angles (Fig. 5).

When the latch is moved into its lower position (Figs. 2 and 5), the rib20 freely enters the slot 14 and the shoulders 21 contact the cheeks 15adjacent the inner edges thereof. The shoulders, by meeting the frontsurfaces 22 of the cheeks almost squarely, do not impart any wedgingaction thereon. Frequent contact between the shoulders 21 and thesurfaces 22 will not impair the cheeks, but may result in trulyflattening of shoulders 21 and the surfaces 22 which initially areslightly rounded due to the method employed in making the needle shankand latch. Such flattening is beneficial and takes place withoutroughening or otherwise impairing the cheeks or the spoon.

As shown in Fig. 6, the hook 12 differs from the con-- ventional designin that the tip thereof comprises a pair of converging faces 24 meetingat an edge 25 substantially parallel to the shank. The upper edge of thehook extends through an arc of about and the lower edge- 0 of the hookextends through an arc of about whereby 3 of this configuration, theforce exerted by the latch on the hook is applied in a substantiallyhorizontal direction, that is, at a point disposed in a planeperpendicular to the longitudinal axis of the shank; and the midpoint ofthe bend of the hook is so close to the vertical section of the shankthat any bending moments are readily resisted by this section because ofits greater width and thickness than that of the conventional midpointof the bend of the hook which is spaced at an arc of 90 from the shank.Consequently, the forces of the latch are absorbed without inducing hookbreakage.

Another advantage derived from the short bend is that the yarn guidesneed barely enter between adjacent needles. This is very desirable infine gauge knitting since it effects shortening of the stroke of theneedle for a latch of a given length and facilitates higher knittingspeeds.

The hook and latch are so constructed and arranged that the tip of thelatch spoon is about in horizontal alignment with or extends justslightly outwardly and above the top of the bend of the hook (Fig. 1),whereby the latch covers the wear point of the needle and stitches arecast off from the latch rather than the hook. This also reduces yarnbreakage when knitting at high speeds.

A still further feature of the short hook is that the latch makescontact therewith when substantially parallel to the longitudinal axisof the shank of the needle.

The hook also is less likely to break due to yarn tension applied at thelower edge adjacent the point because of the short distance to themidpoint of the bend and the resulting small bending moment exerted onthe hook by the yarn. Such forces are further resisted by the heavierthan normal hook cross-section near the point because the bend of thehook is not tapered as it approaches the point.

Also, the bend of the hook has flattened side faces 26 which extendalmost to the tip of the hook.

From the foregoing description, it will be seen that the presentinvention provides a stronger and more durable latch needle thanutilized heretofore Without increasing the weight or dimensions of theneedles but actually reducing the same. Such needles will resistbreakage when used for long periods in connection with machines operatedat the high speeds previously indicated herein.

As various changes may be made in the form, construction and arrangementof the parts herein, without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in any limiting sense.

I claim:

1. A latch needle comprising a shank having a straight upper portion, ahook at the upper portion of said shank having a bend of about andterminating in a tip, a latch for contacting said tip, and means forpivotally mounting said latch on said shank, said tip facing a planepassing through said latch mounting means and the lower portion of saidshank.

2. A latch needle according to claim 1 wherein said latch makes contactwith said tip when substantially parallel to the upper portion of saidshank.

3. A latch needle according to claim 1, wherein the free end of saidlatch extends slightly beyond the outermost portion of the bend of saidhook when said latch contacts said tip.

4. A latch needle according to claim 1, wherein the sides of said hookare flattened from said tip to said shank.

5. A latch needle according to claim 1, wherein said tip consists of apair of converging faces providing an edge contacted by said latchlengthwise with respect to said latch.

6. A latch needle according to claim 1, wherein said shank has alongitudinal slot at the front face thereof below said hook defined by apair of cheeks, and said latch is pivotally mounted in said slot by saidlatching mounting means and has a spoon at its free end provided with asurface on one side for contacting said hook and provided with aconfiguration on the opposite side thereof, said configuration includinga longitudinally extending rib having parallel sides adapted to freelyenter said slot and including shoulders extending lengthwise at therespective sides of said rib and being dispossed at about right anglesthereto thereby providing zones adapted to substantially fiatly contactonly the front surfaces of said cheeks to prevent said spoon from beingwedged into said slot and causing cheek breakage.

References Cited in the file of this patent UNITED STATES PATENTS1,168,039 Swinglehurst Jan. 11, 1916 1,354,096 Fels Sept. 28, 19201,468,518 Scott Sept. 18, 1923 1,752,155 Egly Mar. 25, 1930 1,848,900Messing Mar. 8, 1932 2,249,780 Page July 22, 1941

